Access File Locking

I am running IIS on a win2000 machine linking to an MDB file with php. If the MDB is opened in access the website will display this error when attempting to view the web page:

Warning: SQL error: [Microsoft][ODBC Microsoft Access Driver] Could not use '(unknown)'; file already in use., SQL state S1000 in SQLConnect in c:\inetpub\wwwroot\php\agencydb\extlist.php on line 18
Could Not Make Connection